Ed Pilkington in New York
guardian.co.uk, Thursday 24 February 2011 21.36 GMT
Paul McCartney – with New York City Ballet's ballet master in chief Peter Martins – whose ballet Ocean's Kingdom will debut in September. Photograph: Mpl Communications/PA
Behind a closed door in the main auditorium of the David H Koch theatre in the Lincoln Centre in Manhattan, the New York City Ballet ran through the opening movement of a new score for dance. The full 62-member orchestra performed in front of the composer, who was hearing his work live for the first time.
Even with his unparalleled record, it must have been an anxious moment for Paul McCartney, for whom this is a first foray into the world of ballet. The piece, Ocean's Kingdom, will receive its public outing on 22 September at the start of the ballet company's autumn season.
It is the result of an encounter last year between McCartney and Peter Martins, the artistic leader of the NYCB, at a fundraising event at the company's training school. Martins asked McCartney if he fancied writing a dance score.
McCartney said he was taken by the idea at once. "I am always interested in new directions that I haven't worked in before. What was interesting was writing music that meant something expressively rather than just writing a song. Trying to write something that expressed an emotion, so you have fear, love, anger, sadness to play with, and I found that exciting and challenging."
McCartney is putting final touches to the score with the help of a professional composer, John Wilson. It will then pass for choreography to Martins, a Danish dancer who joined the NYCB under the legendary George Balanchine and has led it for more than 20 years.
The ballet is expected to run to 50 minutes with a cast of up to 45 dancers. McCartney told the New York Times it was "basically a romantic story" involving a clash between the pure world of the ocean kingdom and "baddies" of the earth kingdom. In an echo of Romeo and Juliet, the ocean king's daughter falls for the earth king's brother; trouble ensues.
McCartney's collaboration deepens his connections with New York. Since 2007 he has been in a relationship with Nancy Shevell, who sits on the board of the New York Metropolitan Transportation Authority. The September premiere will also feature a performance of Union Jack, Balanchine's tribute to Britain.
The ballet by the world's most successful songwriter comes at an opportune moment. Ballet is having something of a golden era, boosted in part by the Oscar-nominated film Black Swan.
Over the past 20 years McCartney, 68, has branched out on several occasions into classical music, with two oratorios – Liverpool Oratorio and Ecce Cor Meum – under his belt as well as a poem set to music, called Standing Stone.
His career as a classical composer has been patchy. When the Liverpool Oratorio, which he wrote with Carl Davis, was first performed in 1991 at the Liverpool Anglican cathedral, the Guardian said it "spends most of its time in a lacklustre sub-Puccinian arioso style, except when it descends even further to the level of Eurovision song contest blandness".
The work fared no better when it crossed the Atlantic and was played at the Carnegie Hall. "A sprawling, mawkish and, to this taste, excruciatingly embarrassing, 90-minute exercise of the ego," was how Newsday received it.
McCartney professes to be hardened against the slights of critics. He told the New York Times: "They didn't like She Loves You either. You've just got to read any orchestral reviews or reviews of any art, and there's an awful lot of stuff the critics don't like. If it did worry me, I would give it up all together."